blob: 677f94149e04b0c583df67af3adc447339273091 [file] [log] [blame]
// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "cobalt/renderer/rasterizer/egl/render_tree_node_visitor.h"
#include <algorithm>
#include <cmath>
#include <limits>
#include "base/debug/trace_event.h"
#include "base/logging.h"
#include "base/optional.h"
#include "cobalt/base/polymorphic_downcast.h"
#include "cobalt/base/type_id.h"
#include "cobalt/math/matrix3_f.h"
#include "cobalt/math/transform_2d.h"
#include "cobalt/renderer/rasterizer/common/utils.h"
#include "cobalt/renderer/rasterizer/egl/draw_callback.h"
#include "cobalt/renderer/rasterizer/egl/draw_clear.h"
#include "cobalt/renderer/rasterizer/egl/draw_poly_color.h"
#include "cobalt/renderer/rasterizer/egl/draw_rect_border.h"
#include "cobalt/renderer/rasterizer/egl/draw_rect_color_texture.h"
#include "cobalt/renderer/rasterizer/egl/draw_rect_linear_gradient.h"
#include "cobalt/renderer/rasterizer/egl/draw_rect_radial_gradient.h"
#include "cobalt/renderer/rasterizer/egl/draw_rect_shadow_blur.h"
#include "cobalt/renderer/rasterizer/egl/draw_rect_shadow_spread.h"
#include "cobalt/renderer/rasterizer/egl/draw_rect_texture.h"
#include "cobalt/renderer/rasterizer/egl/draw_rrect_color.h"
#include "cobalt/renderer/rasterizer/egl/draw_rrect_color_texture.h"
#include "cobalt/renderer/rasterizer/skia/hardware_image.h"
#include "cobalt/renderer/rasterizer/skia/image.h"
namespace cobalt {
namespace renderer {
namespace rasterizer {
namespace egl {
namespace {
const render_tree::ColorRGBA kOpaqueWhite(1.0f, 1.0f, 1.0f, 1.0f);
const render_tree::ColorRGBA kTransparentBlack(0.0f, 0.0f, 0.0f, 0.0f);
bool IsOpaque(float opacity) {
return opacity >= 0.999f;
}
math::Rect RoundRectFToInt(const math::RectF& input) {
int left = static_cast<int>(input.x() + 0.5f);
int right = static_cast<int>(input.right() + 0.5f);
int top = static_cast<int>(input.y() + 0.5f);
int bottom = static_cast<int>(input.bottom() + 0.5f);
return math::Rect(left, top, right - left, bottom - top);
}
bool IsOnlyScaleAndTranslate(const math::Matrix3F& matrix) {
const float kEpsilon = 0.0001f;
return std::abs(matrix(0, 1)) < kEpsilon &&
std::abs(matrix(1, 0)) < kEpsilon &&
std::abs(matrix(2, 0)) < kEpsilon &&
std::abs(matrix(2, 1)) < kEpsilon &&
std::abs(matrix(2, 2) - 1.0f) < kEpsilon;
}
math::Matrix3F GetTexcoordTransform(
const OffscreenTargetManager::TargetInfo& target) {
// Flip the texture vertically to accommodate OpenGL's bottom-left origin.
float scale_x = 1.0f / target.framebuffer->GetSize().width();
float scale_y = -1.0f / target.framebuffer->GetSize().height();
return math::Matrix3F::FromValues(
target.region.width() * scale_x, 0, target.region.x() * scale_x,
0, target.region.height() * scale_y, 1.0f + target.region.y() * scale_y,
0, 0, 1);
}
bool ImageNodeSupportedNatively(render_tree::ImageNode* image_node) {
skia::Image* skia_image = base::polymorphic_downcast<skia::Image*>(
image_node->data().source.get());
if (skia_image->GetTypeId() == base::GetTypeId<skia::SinglePlaneImage>() &&
skia_image->CanRenderInSkia()) {
return true;
}
return false;
}
bool RoundedViewportSupportedForSource(render_tree::Node* source) {
base::TypeId source_type = source->GetTypeId();
if (source_type == base::GetTypeId<render_tree::ImageNode>()) {
render_tree::ImageNode* image_node =
base::polymorphic_downcast<render_tree::ImageNode*>(source);
return ImageNodeSupportedNatively(image_node);
} else if (source_type == base::GetTypeId<render_tree::CompositionNode>()) {
// If this is a composition of valid sources, then rendering with a rounded
// viewport is also supported.
render_tree::CompositionNode* composition_node =
base::polymorphic_downcast<render_tree::CompositionNode*>(source);
typedef render_tree::CompositionNode::Children Children;
const Children& children = composition_node->data().children();
for (Children::const_iterator iter = children.begin();
iter != children.end(); ++iter) {
if (!RoundedViewportSupportedForSource(iter->get())) {
return false;
}
}
return true;
}
return false;
}
// Return the error value of a given offscreen taget cache entry.
// |desired_bounds| specifies the world-space bounds to which an offscreen
// target will be rendered.
// |cached_bounds| specifies the world-space bounds used when the offscreen
// target was generated.
// Lower return values indicate better fits. Only cache entries with an error
// less than 1 will be considered suitable.
float OffscreenTargetErrorFunction(const math::RectF& desired_bounds,
const math::RectF& cached_bounds) {
// The cached contents must be within 0.5 pixels of the desired size to avoid
// scaling artifacts.
if (std::abs(desired_bounds.width() - cached_bounds.width()) >= 0.5f ||
std::abs(desired_bounds.height() - cached_bounds.height()) >= 0.5f) {
return 1.0f;
}
// Use the cached contents' sub-pixel offset as the error rating.
math::PointF desired_offset(
desired_bounds.x() - std::floor(desired_bounds.x()),
desired_bounds.y() - std::floor(desired_bounds.y()));
math::PointF cached_offset(
cached_bounds.x() - std::floor(cached_bounds.x()),
cached_bounds.y() - std::floor(cached_bounds.y()));
float error_x = std::abs(desired_offset.x() - cached_offset.x());
float error_y = std::abs(desired_offset.y() - cached_offset.y());
// Any sub-pixel offset is okay. Return something less than 1.
return (error_x + error_y) * 0.49f;
}
float OffscreenTargetErrorFunction1D(float desired, const float& cached) {
return std::abs(cached - desired);
}
} // namespace
RenderTreeNodeVisitor::RenderTreeNodeVisitor(GraphicsState* graphics_state,
DrawObjectManager* draw_object_manager,
OffscreenTargetManager* offscreen_target_manager,
const FallbackRasterizeFunction& fallback_rasterize,
SkCanvas* fallback_render_target,
backend::RenderTarget* render_target,
const math::Rect& content_rect)
: graphics_state_(graphics_state),
draw_object_manager_(draw_object_manager),
offscreen_target_manager_(offscreen_target_manager),
fallback_rasterize_(fallback_rasterize),
fallback_render_target_(fallback_render_target),
render_target_(render_target),
render_target_is_offscreen_(false),
allow_offscreen_targets_(true),
failed_offscreen_target_request_(false),
last_draw_id_(0) {
draw_state_.scissor.Intersect(content_rect);
}
void RenderTreeNodeVisitor::Visit(
render_tree::CompositionNode* composition_node) {
const render_tree::CompositionNode::Builder& data = composition_node->data();
math::Matrix3F old_transform = draw_state_.transform;
draw_state_.transform = draw_state_.transform *
math::TranslateMatrix(data.offset().x(), data.offset().y());
draw_state_.rounded_scissor_rect.Offset(-data.offset());
const render_tree::CompositionNode::Children& children =
data.children();
for (render_tree::CompositionNode::Children::const_iterator iter =
children.begin(); iter != children.end(); ++iter) {
(*iter)->Accept(this);
}
draw_state_.rounded_scissor_rect.Offset(data.offset());
draw_state_.transform = old_transform;
}
void RenderTreeNodeVisitor::Visit(
render_tree::MatrixTransform3DNode* transform_3d_node) {
// This is used in conjunction with a map-to-mesh filter. If that filter is
// implemented natively, then this transform 3D must be handled natively
// as well. Otherwise, use the fallback rasterizer for both.
FallbackRasterize(transform_3d_node);
}
void RenderTreeNodeVisitor::Visit(
render_tree::MatrixTransformNode* transform_node) {
const render_tree::MatrixTransformNode::Builder& data =
transform_node->data();
math::Matrix3F old_transform = draw_state_.transform;
draw_state_.transform = draw_state_.transform *
data.transform;
data.source->Accept(this);
draw_state_.transform = old_transform;
}
void RenderTreeNodeVisitor::Visit(render_tree::FilterNode* filter_node) {
const render_tree::FilterNode::Builder& data = filter_node->data();
// Handle viewport-only filter.
if (data.viewport_filter &&
!data.opacity_filter &&
!data.blur_filter &&
!data.map_to_mesh_filter) {
const math::Matrix3F& transform = draw_state_.transform;
if (data.viewport_filter->has_rounded_corners()) {
// Certain source nodes have an optimized path for rendering inside
// rounded viewports.
if (RoundedViewportSupportedForSource(data.source)) {
DCHECK(!draw_state_.rounded_scissor_corners);
draw_state_.rounded_scissor_rect = data.viewport_filter->viewport();
draw_state_.rounded_scissor_corners =
data.viewport_filter->rounded_corners();
data.source->Accept(this);
draw_state_.rounded_scissor_corners = base::nullopt;
return;
}
} else if (IsOnlyScaleAndTranslate(transform)) {
// Orthogonal viewport filters without rounded corners can be collapsed
// into the world-space scissor.
// Transform local viewport to world viewport.
const math::RectF& filter_viewport = data.viewport_filter->viewport();
math::RectF transformed_viewport(
filter_viewport.x() * transform(0, 0) + transform(0, 2),
filter_viewport.y() * transform(1, 1) + transform(1, 2),
filter_viewport.width() * transform(0, 0),
filter_viewport.height() * transform(1, 1));
// Ensure transformed viewport data is sane (in case global transform
// flipped any axis).
if (transformed_viewport.width() < 0) {
transformed_viewport.set_x(transformed_viewport.right());
transformed_viewport.set_width(-transformed_viewport.width());
}
if (transformed_viewport.height() < 0) {
transformed_viewport.set_y(transformed_viewport.bottom());
transformed_viewport.set_height(-transformed_viewport.height());
}
// Combine the new viewport filter with existing viewport filter.
math::Rect old_scissor = draw_state_.scissor;
draw_state_.scissor.Intersect(RoundRectFToInt(transformed_viewport));
if (!draw_state_.scissor.IsEmpty()) {
data.source->Accept(this);
}
draw_state_.scissor = old_scissor;
return;
}
}
// Handle opacity-only filter.
if (data.opacity_filter &&
!data.viewport_filter &&
!data.blur_filter &&
!data.map_to_mesh_filter) {
const float filter_opacity = data.opacity_filter->opacity();
if (filter_opacity <= 0.0f) {
// Totally transparent. Ignore the source.
return;
} else if (filter_opacity >= 1.0f) {
// Totally opaque. Render like normal.
data.source->Accept(this);
return;
} else if (common::utils::NodeCanRenderWithOpacity(data.source)) {
// Simple opacity that does not require an offscreen target.
float old_opacity = draw_state_.opacity;
draw_state_.opacity *= filter_opacity;
data.source->Accept(this);
draw_state_.opacity = old_opacity;
return;
} else {
// Complex opacity that requires an offscreen target.
math::Matrix3F texcoord_transform(math::Matrix3F::Identity());
math::RectF content_rect;
const backend::TextureEGL* texture = nullptr;
// Render source at 100% opacity to an offscreen target, then render
// that result with the specified filter opacity.
OffscreenRasterize(data.source, &texture, &texcoord_transform,
&content_rect);
if (texture != nullptr) {
if (content_rect.IsEmpty()) {
return;
}
// The content rect is already in screen space, so reset the transform.
math::Matrix3F old_transform = draw_state_.transform;
float old_opacity = draw_state_.opacity;
draw_state_.transform = math::Matrix3F::Identity();
draw_state_.opacity *= filter_opacity;
scoped_ptr<DrawObject> draw(new DrawRectColorTexture(graphics_state_,
draw_state_, content_rect, kOpaqueWhite, texture,
texcoord_transform, false /* clamp_texcoords */));
AddTransparentDraw(draw.Pass(), content_rect);
draw_state_.opacity = old_opacity;
draw_state_.transform = old_transform;
return;
}
}
}
// Handle blur-only filter.
if (data.blur_filter &&
!data.viewport_filter &&
!data.opacity_filter &&
!data.map_to_mesh_filter) {
if (data.blur_filter->blur_sigma() == 0.0f) {
// Ignorable blur request. Render normally.
data.source->Accept(this);
return;
}
}
// No filter.
if (!data.opacity_filter &&
!data.viewport_filter &&
!data.blur_filter &&
!data.map_to_mesh_filter) {
data.source->Accept(this);
return;
}
// Use the fallback rasterizer to handle everything else.
FallbackRasterize(filter_node);
}
void RenderTreeNodeVisitor::Visit(render_tree::ImageNode* image_node) {
const render_tree::ImageNode::Builder& data = image_node->data();
// The image node may contain nothing. For example, when it represents a video
// element before any frame is decoded.
if (!data.source) {
return;
}
if (!IsVisible(image_node->GetBounds())) {
return;
}
if (!ImageNodeSupportedNatively(image_node)) {
FallbackRasterize(image_node);
return;
}
skia::Image* skia_image =
base::polymorphic_downcast<skia::Image*>(data.source.get());
bool clamp_texcoords = false;
bool is_opaque = skia_image->IsOpaque() && IsOpaque(draw_state_.opacity);
// Ensure any required backend processing is done to create the necessary
// GPU resource.
skia_image->EnsureInitialized();
// Calculate matrix to transform texture coordinates according to the local
// transform.
math::Matrix3F texcoord_transform(math::Matrix3F::Identity());
if (IsOnlyScaleAndTranslate(data.local_transform)) {
texcoord_transform(0, 0) = data.local_transform(0, 0) != 0 ?
1.0f / data.local_transform(0, 0) : 0;
texcoord_transform(1, 1) = data.local_transform(1, 1) != 0 ?
1.0f / data.local_transform(1, 1) : 0;
texcoord_transform(0, 2) = -texcoord_transform(0, 0) *
data.local_transform(0, 2);
texcoord_transform(1, 2) = -texcoord_transform(1, 1) *
data.local_transform(1, 2);
if (texcoord_transform(0, 0) < 1.0f || texcoord_transform(1, 1) < 1.0f) {
// Edges may interpolate with texels outside the designated region.
// Use a fragment shader that clamps the texture coordinates to prevent
// that from happening.
clamp_texcoords = true;
}
} else {
texcoord_transform = data.local_transform.Inverse();
}
// Different shaders are used depending on whether the image has a single
// plane or multiple planes.
scoped_ptr<DrawObject> draw;
if (skia_image->GetTypeId() == base::GetTypeId<skia::SinglePlaneImage>()) {
skia::HardwareFrontendImage* hardware_image =
base::polymorphic_downcast<skia::HardwareFrontendImage*>(skia_image);
if (hardware_image->alternate_rgba_format()) {
// We don't yet handle alternative formats that piggyback on a GL_RGBA
// texture. This comes up, for example, with UYVY (YUV 422) textures.
FallbackRasterize(image_node);
return;
}
if (draw_state_.rounded_scissor_corners) {
// Transparency is used to anti-alias the rounded rect.
is_opaque = false;
draw.reset(new DrawRRectColorTexture(graphics_state_, draw_state_,
data.destination_rect, kOpaqueWhite,
hardware_image->GetTextureEGL(), texcoord_transform,
clamp_texcoords));
} else if (clamp_texcoords || !is_opaque) {
draw.reset(new DrawRectColorTexture(graphics_state_, draw_state_,
data.destination_rect, kOpaqueWhite,
hardware_image->GetTextureEGL(), texcoord_transform,
clamp_texcoords));
} else {
draw.reset(new DrawRectTexture(graphics_state_, draw_state_,
data.destination_rect, hardware_image->GetTextureEGL(),
texcoord_transform));
}
} else if (skia_image->GetTypeId() ==
base::GetTypeId<skia::MultiPlaneImage>()) {
FallbackRasterize(image_node);
return;
} else {
NOTREACHED();
return;
}
if (is_opaque) {
AddOpaqueDraw(draw.Pass(), image_node->GetBounds());
} else {
AddTransparentDraw(draw.Pass(), image_node->GetBounds());
}
}
void RenderTreeNodeVisitor::Visit(
render_tree::PunchThroughVideoNode* video_node) {
if (!IsVisible(video_node->GetBounds())) {
return;
}
const render_tree::PunchThroughVideoNode::Builder& data = video_node->data();
math::RectF mapped_rect = draw_state_.transform.MapRect(data.rect);
data.set_bounds_cb.Run(
math::Rect(static_cast<int>(mapped_rect.x()),
static_cast<int>(mapped_rect.y()),
static_cast<int>(mapped_rect.width()),
static_cast<int>(mapped_rect.height())));
scoped_ptr<DrawObject> draw(new DrawPolyColor(graphics_state_,
draw_state_, data.rect, kTransparentBlack));
AddOpaqueDraw(draw.Pass(), video_node->GetBounds());
}
void RenderTreeNodeVisitor::Visit(render_tree::RectNode* rect_node) {
math::RectF node_bounds(rect_node->GetBounds());
if (!IsVisible(node_bounds)) {
return;
}
const render_tree::RectNode::Builder& data = rect_node->data();
const scoped_ptr<render_tree::Brush>& brush = data.background_brush;
math::RectF content_rect(data.rect);
// Only solid color brushes are natively supported with rounded corners.
if (data.rounded_corners && brush &&
brush->GetTypeId() != base::GetTypeId<render_tree::SolidColorBrush>()) {
FallbackRasterize(rect_node);
return;
}
// Determine whether the RectNode's border attribute is supported. Update
// the content and bounds if so.
scoped_ptr<DrawRectBorder> draw_border;
if (data.border) {
draw_border.reset(new DrawRectBorder(graphics_state_, draw_state_,
rect_node));
if (draw_border->IsValid()) {
content_rect = draw_border->GetContentRect();
node_bounds = draw_border->GetBounds();
}
}
const bool border_supported = !data.border || draw_border->IsValid();
// Determine whether the RectNode's background brush is supported.
base::TypeId brush_type = brush ? brush->GetTypeId() :
base::GetTypeId<render_tree::Brush>();
bool brush_is_solid_and_supported =
brush_type == base::GetTypeId<render_tree::SolidColorBrush>();
bool brush_is_linear_and_supported =
brush_type == base::GetTypeId<render_tree::LinearGradientBrush>();
bool brush_is_radial_and_supported =
brush_type == base::GetTypeId<render_tree::RadialGradientBrush>();
scoped_ptr<DrawRectRadialGradient> draw_radial;
if (brush_is_radial_and_supported) {
const render_tree::RadialGradientBrush* radial_brush =
base::polymorphic_downcast<const render_tree::RadialGradientBrush*>
(brush.get());
draw_radial.reset(new DrawRectRadialGradient(graphics_state_, draw_state_,
content_rect, *radial_brush,
base::Bind(&RenderTreeNodeVisitor::GetScratchTexture,
base::Unretained(this), make_scoped_refptr(rect_node))));
brush_is_radial_and_supported = draw_radial->IsValid();
}
const bool brush_supported = !brush || brush_is_solid_and_supported ||
brush_is_linear_and_supported || brush_is_radial_and_supported;
if (!brush_supported || !border_supported) {
FallbackRasterize(rect_node);
return;
}
if (draw_border) {
AddTransparentDraw(draw_border.PassAs<DrawObject>(), node_bounds);
}
// Handle drawing the content.
if (brush_is_solid_and_supported) {
const render_tree::SolidColorBrush* solid_brush =
base::polymorphic_downcast<const render_tree::SolidColorBrush*>
(brush.get());
if (data.rounded_corners) {
scoped_ptr<DrawObject> draw(new DrawRRectColor(graphics_state_,
draw_state_, content_rect, *data.rounded_corners,
solid_brush->color()));
// Transparency is used for anti-aliasing.
AddTransparentDraw(draw.Pass(), node_bounds);
} else {
scoped_ptr<DrawObject> draw(new DrawPolyColor(graphics_state_,
draw_state_, content_rect, solid_brush->color()));
if (IsOpaque(draw_state_.opacity * solid_brush->color().a())) {
AddOpaqueDraw(draw.Pass(), node_bounds);
} else {
AddTransparentDraw(draw.Pass(), node_bounds);
}
}
} else if (brush_is_linear_and_supported) {
const render_tree::LinearGradientBrush* linear_brush =
base::polymorphic_downcast<const render_tree::LinearGradientBrush*>
(brush.get());
scoped_ptr<DrawObject> draw(new DrawRectLinearGradient(graphics_state_,
draw_state_, content_rect, *linear_brush));
// The draw may use transparent pixels to ensure only pixels in the
// specified area are modified.
AddTransparentDraw(draw.Pass(), node_bounds);
} else if (brush_is_radial_and_supported) {
// The colors in the brush may be transparent.
AddTransparentDraw(draw_radial.PassAs<DrawObject>(), node_bounds);
}
}
void RenderTreeNodeVisitor::Visit(render_tree::RectShadowNode* shadow_node) {
math::RectF node_bounds(shadow_node->GetBounds());
if (!IsVisible(node_bounds)) {
return;
}
const render_tree::RectShadowNode::Builder& data = shadow_node->data();
base::optional<render_tree::RoundedCorners> spread_corners =
data.rounded_corners;
scoped_ptr<DrawObject> draw;
render_tree::ColorRGBA shadow_color(data.shadow.color);
math::RectF spread_rect(data.rect);
spread_rect.Offset(data.shadow.offset);
if (data.inset) {
if (spread_corners) {
spread_corners = spread_corners->Inset(
data.spread, data.spread, data.spread, data.spread);
}
spread_rect.Inset(data.spread, data.spread);
if (!spread_rect.IsEmpty() && data.shadow.blur_sigma > 0.0f) {
draw.reset(new DrawRectShadowBlur(graphics_state_, draw_state_,
data.rect, data.rounded_corners, spread_rect, spread_corners,
shadow_color, data.shadow.blur_sigma, data.inset));
} else {
draw.reset(new DrawRectShadowSpread(graphics_state_, draw_state_,
spread_rect, spread_corners, data.rect, data.rounded_corners,
shadow_color));
}
} else {
if (spread_corners) {
spread_corners = spread_corners->Inset(
-data.spread, -data.spread, -data.spread, -data.spread);
}
spread_rect.Outset(data.spread, data.spread);
if (spread_rect.IsEmpty()) {
// Negative spread shenanigans! Nothing to draw.
return;
}
if (data.shadow.blur_sigma > 0.0f) {
draw.reset(new DrawRectShadowBlur(graphics_state_, draw_state_,
data.rect, data.rounded_corners, spread_rect, spread_corners,
shadow_color, data.shadow.blur_sigma, data.inset));
} else {
draw.reset(new DrawRectShadowSpread(graphics_state_, draw_state_,
data.rect, data.rounded_corners, spread_rect, spread_corners,
shadow_color));
}
}
// Transparency is used to skip pixels that are not shadowed.
AddTransparentDraw(draw.Pass(), node_bounds);
}
void RenderTreeNodeVisitor::Visit(render_tree::TextNode* text_node) {
if (!IsVisible(text_node->GetBounds())) {
return;
}
FallbackRasterize(text_node);
}
// Get a scratch texture row region for use in rendering |node|.
void RenderTreeNodeVisitor::GetScratchTexture(
scoped_refptr<render_tree::Node> node, float size,
DrawObject::TextureInfo* out_texture_info) {
// Get the cached texture region or create one.
OffscreenTargetManager::TargetInfo target_info;
bool cached = offscreen_target_manager_->GetCachedOffscreenTarget(node,
base::Bind(&OffscreenTargetErrorFunction1D, size), &target_info);
if (!cached) {
offscreen_target_manager_->AllocateOffscreenTarget(node, size, size,
&target_info);
}
out_texture_info->texture = target_info.framebuffer == nullptr ? nullptr :
target_info.framebuffer->GetColorTexture();
out_texture_info->region = target_info.region;
out_texture_info->is_new = !cached;
}
// Get an offscreen target to render |node|.
// |out_content_cached| is true if the node's contents are already cached in
// the returned offscreen target.
// |out_target_info| describes the offscreen surface into which |node| should
// be rendered.
// |out_content_rect| is the onscreen rect (already in screen space) where the
// offscreen contents should be rendered.
void RenderTreeNodeVisitor::GetOffscreenTarget(
scoped_refptr<render_tree::Node> node,
bool* out_content_cached,
OffscreenTargetManager::TargetInfo* out_target_info,
math::RectF* out_content_rect) {
// Default to telling the caller that nothing should be rendered.
*out_content_cached = true;
out_content_rect->SetRect(0.0f, 0.0f, 0.0f, 0.0f);
if (!allow_offscreen_targets_) {
failed_offscreen_target_request_ = true;
return;
}
math::RectF node_bounds(node->GetBounds());
math::RectF mapped_bounds(draw_state_.transform.MapRect(node_bounds));
if (mapped_bounds.IsEmpty()) {
return;
}
// Request a slightly larger render target than the calculated bounds. The
// rasterizer may use an extra pixel along the edge of anti-aliased objects.
const float kBorderWidth = 1.0f;
math::PointF content_offset(
std::floor(mapped_bounds.x() - kBorderWidth),
std::floor(mapped_bounds.y() - kBorderWidth));
math::SizeF content_size(
std::ceil(mapped_bounds.right() + kBorderWidth - content_offset.x()),
std::ceil(mapped_bounds.bottom() + kBorderWidth - content_offset.y()));
// Get a suitable cache of the render tree node if one exists, or allocate
// a new offscreen target if possible. The OffscreenTargetErrorFunction will
// determine whether any caches are fit for use.
// Do not cache rotating nodes since these will result in inappropriate
// reuse of offscreen targets. Transforms that are rotations of angles in
// the first quadrant will produce the same mapped rect sizes as angles in
// the other 3 quadrants. Also avoid caching reflections.
bool allow_caching = IsOnlyScaleAndTranslate(draw_state_.transform) &&
draw_state_.transform(0, 0) > 0.0f &&
draw_state_.transform(1, 1) > 0.0f;
if (allow_caching) {
*out_content_cached = offscreen_target_manager_->GetCachedOffscreenTarget(
node, base::Bind(&OffscreenTargetErrorFunction, mapped_bounds),
out_target_info);
if (!(*out_content_cached)) {
offscreen_target_manager_->AllocateOffscreenTarget(node,
content_size, mapped_bounds, out_target_info);
} else {
// Maintain the size of the cached contents to avoid scaling artifacts.
content_size = out_target_info->region.size();
}
} else {
*out_content_cached = false;
out_target_info->framebuffer = nullptr;
}
// If no offscreen target could be allocated, then the render tree node will
// be rendered directly onto the main framebuffer. Use the current scissor
// to minimize what has to be drawn.
if (out_target_info->framebuffer == nullptr) {
math::RectF content_bounds(content_offset, content_size);
content_bounds.Intersect(draw_state_.scissor);
if (content_bounds.IsEmpty()) {
return;
}
content_offset = content_bounds.origin();
content_size = content_bounds.size();
}
out_content_rect->set_origin(content_offset);
out_content_rect->set_size(content_size);
}
void RenderTreeNodeVisitor::FallbackRasterize(
scoped_refptr<render_tree::Node> node) {
OffscreenTargetManager::TargetInfo target_info;
math::RectF content_rect;
bool content_is_cached = false;
GetOffscreenTarget(node, &content_is_cached, &target_info, &content_rect);
if (content_rect.IsEmpty()) {
return;
}
// If no offscreen target was available, then just render directly onto the
// current render target.
if (target_info.framebuffer == nullptr) {
base::Closure rasterize_callback = base::Bind(fallback_rasterize_,
node, fallback_render_target_, draw_state_.transform, content_rect,
draw_state_.opacity, kFallbackShouldFlush);
scoped_ptr<DrawObject> draw(new DrawCallback(rasterize_callback));
AddExternalDraw(draw.Pass(), content_rect, node->GetTypeId());
return;
}
// Setup draw for the contents as needed.
if (!content_is_cached) {
// Cache the results when drawn with 100% opacity, then draw the cached
// results at the desired opacity. This avoids having to generate different
// caches under varying opacity filters.
float old_opacity = draw_state_.opacity;
draw_state_.opacity = 1.0f;
FallbackRasterize(node, target_info, content_rect);
draw_state_.opacity = old_opacity;
}
// Sub-pixel offsets are passed to the fallback rasterizer to preserve
// sharpness. The results should be drawn to |content_rect| which is already
// in screen space.
math::Matrix3F old_transform = draw_state_.transform;
draw_state_.transform = math::Matrix3F::Identity();
// Create the appropriate draw object to call the draw callback, then render
// its results onscreen. A transparent draw must be used even if the current
// opacity is 100% because the contents may have transparency.
backend::TextureEGL* texture = target_info.framebuffer->GetColorTexture();
math::Matrix3F texcoord_transform = GetTexcoordTransform(target_info);
if (IsOpaque(draw_state_.opacity)) {
scoped_ptr<DrawObject> draw(new DrawRectTexture(graphics_state_,
draw_state_, content_rect, texture, texcoord_transform));
AddTransparentDraw(draw.Pass(), content_rect);
} else {
scoped_ptr<DrawObject> draw(new DrawRectColorTexture(graphics_state_,
draw_state_, content_rect, kOpaqueWhite, texture, texcoord_transform,
false /* clamp_texcoords */));
AddTransparentDraw(draw.Pass(), content_rect);
}
draw_state_.transform = old_transform;
}
void RenderTreeNodeVisitor::FallbackRasterize(
scoped_refptr<render_tree::Node> node,
const OffscreenTargetManager::TargetInfo& target_info,
const math::RectF& content_rect) {
// It is not permitted to render to an offscreen target while already
// rendering to an offscreen target. To allow this path, ensure that
// render targets are not used as both the read and write targets for any
// call. (Although these reads and writes should occur in different regions
// of the target, not all drivers may handle this properly.) Also ensure the
// draw object manager will sort these draws properly.
DCHECK(!render_target_is_offscreen_);
uint32_t rasterize_flags = 0;
// Pre-translate the content so it starts in target_info.region.
math::Matrix3F content_transform =
math::TranslateMatrix(target_info.region.x() - content_rect.x(),
target_info.region.y() - content_rect.y()) *
draw_state_.transform;
base::Closure rasterize_callback = base::Bind(fallback_rasterize_,
node, target_info.skia_canvas, content_transform, target_info.region,
draw_state_.opacity, rasterize_flags);
scoped_ptr<DrawObject> draw(new DrawCallback(rasterize_callback));
backend::RenderTarget* old_render_target = render_target_;
bool old_render_target_is_offscreen = render_target_is_offscreen_;
render_target_ = target_info.framebuffer;
render_target_is_offscreen_ = true;
AddExternalDraw(draw.Pass(), target_info.region, node->GetTypeId());
render_target_ = old_render_target;
render_target_is_offscreen_ = old_render_target_is_offscreen;
}
// Add draw objects to render |node| to an offscreen render target at
// 100% opacity.
// |out_texture| and |out_texcoord_transform| describe the texture subregion
// that will contain the result of rendering |node|. If not enough memory
// is available for the offscreen target, then |out_texture| will be null.
// |out_content_rect| describes the onscreen rect (in screen space) which
// should be used to render node's contents.
void RenderTreeNodeVisitor::OffscreenRasterize(
scoped_refptr<render_tree::Node> node,
const backend::TextureEGL** out_texture,
math::Matrix3F* out_texcoord_transform,
math::RectF* out_content_rect) {
OffscreenTargetManager::TargetInfo target_info;
bool content_is_cached = false;
GetOffscreenTarget(node, &content_is_cached, &target_info, out_content_rect);
if (out_content_rect->IsEmpty()) {
return;
}
if (target_info.framebuffer == nullptr) {
// No offscreen target was available.
*out_texture = nullptr;
return;
}
*out_texture = target_info.framebuffer->GetColorTexture();
*out_texcoord_transform = GetTexcoordTransform(target_info);
if (!content_is_cached) {
// Cache the results at 100% opacity. The caller is responsible for
// drawing the cached results at the desired opacity. This avoids having
// to generate different caches under varying opacity filters.
float old_opacity = draw_state_.opacity;
draw_state_.opacity = 1.0f;
// Try to use the native rasterizer to handle the offscreen rendering.
// However, because offscreen targets are actually regions of a texture
// atlas, some drivers may not properly handle reading and writing to
// the same texture -- even if the operations occur in different regions.
// So native offscreen handling can only occur if |node| or its children
// do not also need offscreen targets (or this particular target). The
// alternative is to use the fallback rasterizer since it allocates its
// own render targets as needed.
//
// Ideally, pre-check |node| and its children to see if they will need
// an offscreen target. However, this would result in a lot of duplicate
// code. So just process the nodes into draws, and if any of them requests
// an offscreen target, then remove all the recently added draws, and use
// the fallback rasterizer instead of the native rasterizer.
uint32_t last_valid_draw_id = last_draw_id_;
bool old_allow_offscreen_targets = allow_offscreen_targets_;
bool old_failed_offscreen_target_request = failed_offscreen_target_request_;
allow_offscreen_targets_ = false;
failed_offscreen_target_request_ = false;
// Push a new render state to rasterize to the offscreen render target.
DrawObject::BaseState old_draw_state = draw_state_;
SkCanvas* old_fallback_render_target = fallback_render_target_;
backend::RenderTarget* old_render_target = render_target_;
bool old_render_target_is_offscreen = render_target_is_offscreen_;
// Adjust the transform to render into target_info.region.
draw_state_.transform =
math::TranslateMatrix(target_info.region.x() - out_content_rect->x(),
target_info.region.y() - out_content_rect->y()) *
draw_state_.transform;
draw_state_.scissor = RoundRectFToInt(target_info.region);
fallback_render_target_ = target_info.skia_canvas;
render_target_ = target_info.framebuffer;
render_target_is_offscreen_ = true;
node->Accept(this);
draw_state_ = old_draw_state;
fallback_render_target_ = old_fallback_render_target;
render_target_ = old_render_target;
render_target_is_offscreen_ = old_render_target_is_offscreen;
bool use_fallback_rasterizer = failed_offscreen_target_request_;
allow_offscreen_targets_ = old_allow_offscreen_targets;
failed_offscreen_target_request_ = old_failed_offscreen_target_request;
if (use_fallback_rasterizer) {
// The node or one of its children needed an offscreen target, so this
// cannot be rendered natively. Remove all the draws added for |node|,
// and just use the fallback rasterizer instead.
draw_object_manager_->RemoveDraws(last_valid_draw_id);
FallbackRasterize(node, target_info, *out_content_rect);
}
draw_state_.opacity = old_opacity;
}
}
bool RenderTreeNodeVisitor::IsVisible(const math::RectF& bounds) {
math::RectF intersection = IntersectRects(
draw_state_.transform.MapRect(bounds), draw_state_.scissor);
return !intersection.IsEmpty();
}
void RenderTreeNodeVisitor::AddOpaqueDraw(scoped_ptr<DrawObject> object,
const math::RectF& local_bounds) {
base::TypeId draw_type = object->GetTypeId();
if (render_target_is_offscreen_) {
last_draw_id_ = draw_object_manager_->AddOffscreenDraw(object.Pass(),
DrawObjectManager::kBlendNone, draw_type, render_target_,
draw_state_.transform.MapRect(local_bounds));
} else {
last_draw_id_ = draw_object_manager_->AddOnscreenDraw(object.Pass(),
DrawObjectManager::kBlendNone, draw_type, render_target_,
draw_state_.transform.MapRect(local_bounds));
}
}
void RenderTreeNodeVisitor::AddTransparentDraw(scoped_ptr<DrawObject> object,
const math::RectF& local_bounds) {
base::TypeId draw_type = object->GetTypeId();
if (render_target_is_offscreen_) {
last_draw_id_ = draw_object_manager_->AddOffscreenDraw(object.Pass(),
DrawObjectManager::kBlendSrcAlpha, draw_type, render_target_,
draw_state_.transform.MapRect(local_bounds));
} else {
last_draw_id_ = draw_object_manager_->AddOnscreenDraw(object.Pass(),
DrawObjectManager::kBlendSrcAlpha, draw_type, render_target_,
draw_state_.transform.MapRect(local_bounds));
}
}
void RenderTreeNodeVisitor::AddExternalDraw(scoped_ptr<DrawObject> object,
const math::RectF& world_bounds, base::TypeId draw_type) {
if (render_target_is_offscreen_) {
last_draw_id_ = draw_object_manager_->AddOffscreenDraw(object.Pass(),
DrawObjectManager::kBlendExternal, draw_type, render_target_,
world_bounds);
} else {
last_draw_id_ = draw_object_manager_->AddOnscreenDraw(object.Pass(),
DrawObjectManager::kBlendExternal, draw_type, render_target_,
world_bounds);
}
}
} // namespace egl
} // namespace rasterizer
} // namespace renderer
} // namespace cobalt